1. Field of the Invention
The present invention relates to metal coil composites having one of more retroflective surfaces and their use in providing temporary traffic signs and fascia display patterns for outdoor use.
2. Discussion of the Background
Various composite laminates are known wherein a metal sheet is laminated with a thermoplastic synthetic resin sheet. U.S. Pat. No 4,508,425 discloses a mirror-like surface manufactured by plating chromium on one surface of a metal sheet bonded to a composite sheet, made up of a synthetic resin sheet and the metal sheet, to form the mirror surface. The mirrored finish sheet may be worked to a desired shape and may be formed with a decorative pattern.
U.S. Pat. No..4,560,623 discloses a specular product of a bronze-like tone particularly suitable for use as a decorative material. The specular product uses, as a substrate, a composite board comprising a synthetic resin sheet and metal sheets laminated thereon, and includes a nickel deposit plated on the metal sheet and a specular film of Sn-Ni alloy electroplated on the nickel deposit using a specific electroplating bath.
Such composites are useful for a number of architectural applications, because the composites combine light weight with high strength. These composites may be used as finished surfaces for all or some portion of the interior or exterior surfaces of a building.
In 1991, the Intermodal Surface Transportation Efficiency Action was passed, requiring the U.S. Secretary of Transportation to institute measures to enhance the crashworthy performance of roadside features, such as traffic signs. This prompted the adoption in 1993 of National Highway Research Program Report,350 (NCHRP Report 350) containing recommended procedures for safety performance evaluation of these highway features. All new or replacement features used on the National Highway System must be tested and pass the guidelines of NCHRP 350.
NCHRP 350 contains guidelines for four categories of highway features. Work zone features such as portable signage and stand assemblies are classified as Category 2 devices. The general test for Category 2 devices requires crash testing an 820 kg vehicle into two devices, one head on to the vehicle and the second turned at a 90xc2x0 angle to the first and spaced 6 meters apart. The vehicle must strike this configuration at 100 km/h, with the event being recorded by still photography and film on video. In order to pass the test, the Category 2 device cannot penetrate or seriously deform the occupant compartment and cannot damage the windshield to the vehicle. That visibility is significantly impaired.
Current and temporary work zone signs are made from sheets of aluminum. Unfortunately, such aluminum signs have not been able to pass this crash test at normal operating heights for portable work zone signs. As a result, the industry has switched to lightweight roll-up signs to pass the NCHRP requirements. However, there is a severe compromise in the use of such signs. The roll-up signs are not rigid enough and are more difficult to fabricate than the conventional rigid aluminum signs.
Accordingly, one object of the present invention is to provide a material for, highway signage that has the required rigidity for long lifetimes and is easy to fabricate using conventional fabrication methods in the highway sign industries while also being able to pass the NCHRP 350 standard.
A further object of the present invention is to provide a metal-resin composite having a retroflective surface typically used in highway signage in construction work zones.
A further object of the present invention is to provide a highway sign, preferably portable, having high rigidity and ease of fabrication while still passing the NCHRP 350 standard.
It is another objection of the present invention to provide a method for preparing a retroflective sheeted composite metal plate or composite, which may be bent to a sharp angle without cracking of the sheeting.
These and other objects of the present invention have been satisfied by the discovery of a metal-resin composite laminated metal sheet comprising:
a resin sheet; and
at least one retroflective surfaced metal sheet laminated onto a surface of said resin sheet; wherein said retroflective surfaced metal sheet comprises;
a metal substrate having an interior and exterior surface with said interior surface adhered to said resin sheet; and
a retroflective sheeting adhered to said exterior surface of said metal substrate by a layer of adhesive, and its use in the construction of signs, particularly highway signs for temporary or permanent use.